I've encountered the same issue when trying to use conda environments in CI builds and Docker images. The [conda documentation][1] does provide an example when using Travis CI, but it does not work for me.

However, via [this blog][2] I found a working solution! Instead of activating your environment, you can use it by calling `conda run -n my_env python my_file.py`. So, keep everything like it was until you activate your environment.

These build specs worked for me when using AWS CodeBuild:

```json
{
  "version": "0.2",
  "phases": {
    "pre_build": {
      "commands": [
        "wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh -q",
        "bash miniconda.sh -b -p $HOME/miniconda",
        ". \"$HOME/miniconda/etc/profile.d/conda.sh\"",
        "hash -r",
        "conda config --set always_yes yes --set changeps1 no",
        "conda update -q conda",
        "conda info -a",
        "conda env create -q -p ./py_env -f environment.yml"
      ]
    },
    "build": {
      "commands": [
        "conda run -p ./py_env python app.py"
      ]
    }
  }
}

```


  [1]: https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/use-conda-with-travis-ci.html
  [2]: https://pythonspeed.com/articles/activate-conda-dockerfile/